Abstract:
Using LIF technique, the distribution of vibrational temperature of I_2 along a supersonic jet axis has been measured, He, Ar and N_2 are used as carrier gases, The vibrational relaxation cross-section has been estimated, based on the “sudden freeze” model. The classical Landau-Teller theory can not be used to explicate that phenomenon: the vibrational relaxation cross-section become larger in low temperature. The mechanism of vibrational relaxation in jets has been analysed with the “orbiting resonance” model qualitatively.